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<H1 class="no-header">clear 1</H1>
<PRE>
<STRONG><A HREF="clear.1.html">clear(1)</A></STRONG>                                                       <STRONG><A HREF="clear.1.html">clear(1)</A></STRONG>




</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
       <STRONG>clear</STRONG> - clear the terminal screen


</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
       <STRONG>clear</STRONG>


</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
       <STRONG>clear</STRONG>  clears  your  screen if this is possible, including
       its scrollback buffer (if the extended "E3" capability  is
       defined).  <STRONG>clear</STRONG> looks in the environment for the terminal
       type given by the environment variable <STRONG>TERM</STRONG>, and  then  in
       the  <STRONG>terminfo</STRONG>  database  to  determine  how  to  clear the
       screen.

       <STRONG>clear</STRONG> writes to the standard output.  You can redirect the
       standard output to a file (which prevents <STRONG>clear</STRONG> from actu-
       ally clearing the screen), and later <STRONG>cat</STRONG> the file  to  the
       screen, clearing it at that point.

       <STRONG>clear</STRONG>  ignores  any  command-line  parameters  that may be
       present.  The  analogous  "<STRONG>tput</STRONG>  clear"  has  command-line
       parameters  including  <STRONG>-T</STRONG> for overriding the <STRONG>TERM</STRONG> environ-
       ment variable.


</PRE><H2><a name="h2-HISTORY">HISTORY</a></H2><PRE>
       A <STRONG>clear</STRONG> command appeared in  2.79BSD  dated  February  24,
       1979.  Later that was provided in Unix 8th edition (1985).

       AT&amp;T  adapted a different BSD program (<STRONG>tset</STRONG>) to make a new
       command (<STRONG>tput</STRONG>), and used this to replace the <STRONG>clear</STRONG> command
       with a shell script which calls <STRONG>tput</STRONG> <STRONG>clear</STRONG>, e.g.,

         /usr/bin/tput ${1:+-T$1} clear 2&gt; /dev/null
         exit

       In 1989, when Keith Bostic revised the BSD <STRONG>tput</STRONG> command to
       make it similar to the AT&amp;T <STRONG>tput</STRONG>, he added a shell  script
       for the <STRONG>clear</STRONG> command:

         exec tput clear

       The  remainder  of  the script in each case is a copyright
       notice.

       The ncurses <STRONG>clear</STRONG> command began in 1995  by  adapting  the
       original BSD <STRONG>clear</STRONG> command (with terminfo, of course).

       The <STRONG>E3</STRONG> extension came later:

       <STRONG>o</STRONG>   In June 1999, xterm provided an extension to the stan-
           dard control sequence for clearing the screen.  Rather
           than  clearing  just  the  visible  part of the screen
           using

             printf '\033[2J'

           one could clear the <EM>scrollback</EM> using

             printf '\033[<STRONG>3</STRONG>J'

           This is documented in <EM>XTerm</EM>  <EM>Control</EM>  <EM>Sequences</EM>  as  a
           feature originating with xterm.

       <STRONG>o</STRONG>   A  few  other terminal developers adopted the feature,
           e.g., PuTTY in 2006.

       <STRONG>o</STRONG>   In April 2011, a Red Hat developer submitted  a  patch
           to  the  Linux kernel, modifying its console driver to
           do the same thing.  The Linux change, part of the  3.0
           release,  did not mention xterm, although it was cited
           in the Red Hat bug report (#683733) which led  to  the
           change.

       <STRONG>o</STRONG>   Again,  a  few  other  terminal developers adopted the
           feature.  But the next relevant step was a  change  to
           the  <STRONG>clear</STRONG>  program in 2013 to incorporate this exten-
           sion.

       <STRONG>o</STRONG>   In 2013, the <STRONG>E3</STRONG> extension was overlooked in <STRONG>tput</STRONG>  with
           the  "clear" parameter.  That was addressed in 2016 by
           reorganizing <STRONG>tput</STRONG> to share its logic  with  <STRONG>clear</STRONG>  and
           <STRONG>tset</STRONG>.


</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
       Neither  IEEE Std 1003.1/The Open  Group  Base  Specifica-
       tions  Issue  7 (POSIX.1-2008) nor X/Open Curses  Issue  7
       documents tset or reset.

       The  latter documents <STRONG>tput</STRONG>, which could be used to replace
       this utility either via a shell  script  or  by  an  alias
       (such as a symbolic link) to run <STRONG>tput</STRONG> as <STRONG>clear</STRONG>.


</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
       <STRONG><A HREF="tput.1.html">tput(1)</A></STRONG>, <STRONG><A HREF="terminfo.5.html">terminfo(5)</A></STRONG>

       This describes <STRONG>ncurses</STRONG> version 6.0 (patch 20170401).



                                                               <STRONG><A HREF="clear.1.html">clear(1)</A></STRONG>
</PRE>
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<li><a href="#h2-NAME">NAME</a></li>
<li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
<li><a href="#h2-DESCRIPTION">DESCRIPTION</a></li>
<li><a href="#h2-HISTORY">HISTORY</a></li>
<li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
<li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
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